Cam operated timing mechanism



Feb. 23, 1965 R. L. BERG 3,170,996

CAM OPERATED TIMING MECHANISM Filed July 20, 1962 FIG.4

INVENTOR.

Ralph L. Berg Attorney United States Patent Office 3 3,170,996 CAM OPERATED TIMING MECHANISM Ralph L. Berg, Crystal Lake, 11]., assignor to Controls Company of America, Schiller Park, 111., a corporation of Delaware Filed July 20, 1962, Ser. No. 211,359

10 Claims. (Cl. 200-38) This invention relates to motor driven timers of the type which operate a function switch at the end of a preset time period. These timers are generally used to perform a single predetermined function at the end of a preset time period such as starting or stopping the operation of an electric appliance.

The primary object of this invention is to provide a means for manually selecting different functions to be performed by the timer at the end of the selected time period.

Timers of this type generally have a switch which is actuated at the end of a predetermined time interval. An adjustable limit stop is positioned in the switch to limit the movement of the switch blade in one direction or the other so that it operates either as an off-on or on-olf switch. The advantages of such a system are best shown by the following example. In operating a home air con ditioner, it is desirable to have the air conditioner turned on some time before youarrive at home and turned off after you have retired- The present timer can beset to Other objects and advantages will be pointed out in or be apparent from the specification-and claims, as will obvious modifications ofthe single embodiment the drawings, in which:"

FIG. 1 is a schematic diagram circuit controlled thereby; FIG. 2 is an end view moved;

FIG. 3 is a view similar to FIG. 2 showing-an alternate position for the selector cam;

"FIG. 4 is a view taken on line 4-4 of FIG. 2 showing theselector and friction clutch arrangement; and

FIG. 5. is a, side view partly broken away showing the timer motordrive.

Referring more particularly to the circuit diagram, FIG.

or the timer-and the of the timer with the cover re- 1,. a timing motor 10.i s-shown connected to drive cam 12 through friction clutch l4. The cam is manually set by turning selector knob 16in either direction to the desired. time interval. On turning the cam, cam follower 18 on switch blade 20 will be cammedout of notch 22 in the cam closing'the switch blade with secondary switch blade 24. This will energize the timer motor circuit, that is, from L to L through switch blade 20, secondary blade 24, and line 26. The energization of electrical appliance '28 connected in line 30 will depend on the position of manual selector segment 32.

7 If the selector segment is in the o positiontandthe cam is set to operate for a preselected interval switch blade 2 will be cammed into engagement with contact 34 closing appliance circuit 30 connected between L and L shown in Patented Feb. 23, 1965 The electrical appliance will then be on for the time period selected. The switch blade will also be cammed into engagement with secondary blade 24 closing the timing motor circuit. At the end of the time period, cam follower 18wil1 drop into notch 22 opening the switch blade with secondary blade 24 and contact 34. The switch blade will engage limit stop, 36 on the selector segment preventing its closure with contact 38 and both circuits will now be'open. t e

If the selector segment is in the on? position and the timer is turned to the desired time interval, switch blade 20 will be cammed. into engagement with stop 40 on the segment opening the appliance circuit. The switch blade will close with secondary blade 24 closing the timing motor circuit. The electrical appliance will now be off for the interval of time set on the timer and will be turned on at the end of the selected time period when cam follower 18 drops into notch 22.

' The timer shown in FIG. 5 has timer motor. 10 mounted on housing 42. A gear train (not shown) is provided in theenlarged portion of the timer motor housing with drive shaft 43 extending into housing 42 through bearing 45. Worm gear 44 is mounted on the end of the drive 'tion clutch 14 which is squeezed betweengwr, 51 and lost motion arbor 58. The friction clutch is connected to'the arbor by means of a finger 60. which extends into a notch 62 on the arbor. Timing cam 12 is mounted to rotate freely on the arbor and is held thereonbynut 63.

The timing cam islimited in its movementb'y dog on the lost motionarbo'r which extendsjinto notch 22 in the cam. When cam follower 18 drops'inton'otch 22 the cam will be, free to move independently of the shaft within the limits of notch 22 thereby providing a" snap action} in the switch operation.

In operation, selector knob 16 mounted on theendof the cam shaft is turned to rotate the carntothe desired.

time setting. On turning the knob, thetiming will cam switch blade 20 upwardagainst secondaryblade 24 andeither limit stop 40 or contact 34 depending on the position of selector segment 32. The timermotor will be energized when blade 20 engages blade 21la'nd will drive the timing cam back to the starting point. When cam follower 18 drops into notch 22 in the cam, it will force the timing camahead at a faster rate the cam shaft through the camming actionof thecarn follower on notch 22 providing a snap action .in the movement of the switch blade vintoor, out .of engagement with the contacts. e

Segment 32 issecured to shaft 66 and is rotated from an on position to an fofl position by means ofa selector knob 68. In the positionshown in FIGS. 1 and 2,

the segment is in the off? position since the appliance circuit isopened at the end of the selectedtime interval.

In FIG, 3 theselector segment is shown turnedto the on" position with the switch blade in contact with contact 38 when. thecam follower drops into notch 22.

Although but one embodiment of;the present invention has been illustrated and described; it will be apparent to those skilled in the art that various changes and modificavtions may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A timing device comprising, in combination,

a timing motor,

timing cam means connected to and driven by said tim ing motor,

switch means connected with said cam means and ineluding a switch member movable selectively between two operative closed circuit positions in response to movement of said cam means, said switch member biased toward one of its operative positions and movable against said bias to the other of its operative positions by said cam means,

selector means having a first position in the path of movement of said movable switch member for engagement therewith to limit travel of said movable switch member toward one of its operative positions and a second position in the path of movement of said movable switch member for engagement therewith to limit travel of said movable switch member toward its other operative position,

and means for selectively positioning said selector means in its first and second positions whereby said timing device is adapted to provide olf-to-on or onto-off operation. A 1

2; The timing device of claim 1 wherein said cam means includes a first cam portion for moving said movable .switch member against said bias to said otheroperative switch member position and a second cam portion spaced from said first cam portion transversely with respect to the direction of cam movement for releasing said movable switch member for movement to the said one operative switch member position, said cam portions being relatively spaced in said direction of cam movement tdsequentially engage and operate said switch means, 7 v a and further including over-running clutch means hetween said cam means and saidtimer motor, and means for moving said cam means independently of said timer motor'for setting said cam means with respect to said switch blade to achieve a predetermined time interval in operation between said first and second cam portions.

3i The timingdevice of claim 2 wherein the driving connection between'said timing cam and said timer motor includes means. providing lost motion therebetween 'so that transition from said first and second cam portions is notsolely dependent on the timer motor but is achieved with a snap action. 1 I I 4. A timingdevice comprising, in combination, atiming motor, I I a rotatable cam connected to, and driven by said cam motor, V a a cam following switch blade biased into engagement with the periphery of said cam, 1

, first circuit means arranged for engagement by said switchfblade when said switch blade isriding on-said cam periphery, 7

said "cam periphery including an operating portion spaced from'the remainder of said cam periphery in a radial direction with respect to the axis of rotation of said cam so that said switch blade moves radially of said cam, and out of engagement with said first circuit means upon registry with said cam operating portion,

second circuit means arranged for engagement with said switch blade when said switch blade is in registry with said cam operating portion,

" a selector member having a'first position in the path of movement of said switch blade for engagement there- "with to limit travel of said switch blade toward'said first circuit means and a second position in the path of movement of said-switch blade for engagement 4 therewith to limit travel of said switch blade toward said second circuit means, and means for selectively positioning said selector member in its first and second positions. 5. The timing device'of claim 4 including a drive shaft connected to and driven by said timing motor, means mounting said cam freely on and for movement relative to said drive shaft, said mounting means also including means providing a lostmotion driving connection between said cam and said drive shaft to provide a driving connection therebetween after a predetermined amount of angular movementtof said cam means with respect to said drive shaft. 6. The timing device of claim 5 including third circuit means arranged for engagement with said switch blade when said switch blade is in engagement with said cam periphery, said third circuit means being connected to and energizing said timing motor when engaged by said'switch blade.

7. The timing device of claim 5 wherein said switch blade is arranged for engagement with said third circuit means when said switch blade is out of engagement with said operating portion of said cam periphery and said switch blade moves out of engagement with said third circuit means when said switch blade is in registry with said cam operating portion.

8. The timing device of claim 5 wherein said cam operating portion is in the form of a notch in the cam periphery into which said switch blade drops when said notch registers with said switch blade. v V

9. A timing device comprising, in combination,

a timing motor,

a drive shaft connected to and driven by said timing i and for movement with said drive shaft and operative to provide a predetermined amount'of angular movement of said cam means with respect to said driveshaft,

alcam following switch blade biased into engagement with the periphery of said cam,

" '1 first circuit means arranged for engagement with said switch blade when said switch blade is in engagement with said cam periphery,

said cam including an operating portion spaced radially from said cam periphery so that said switch blade moves radially of said cam means upon registry with said cam operating portion to move said switch blade out of engagement with said first c ircuit means,

second circuit means arranged for engagement with said switch blade when said switch blade is in registry with said cam operating portion,

third circuit means arranged for engagement with said i switch blade when said switch blade is in'engage 'ment with and riding on said cam periphery, said third circuit means connected to and controlling energization of said timing motor with the duration of engagement of said switch blade with said cam periphery determining a time interval beforeregistry of said operating portion and said switch blade,

a selector member having a first position in the path of movement of said switch blade for engagement therewith to limit travel of said switch blade toward said first circuit means and a second position in the path of movement of said, switch blade for engagement therewith to limit travel of said switch blade toward said second circuit means, said selector member in 1 both its first and second positions permitting sufii- 7 cient movement of said switch blade for. engagea ment with said third circuit means,

, and means for selectively positioning said selector member in its first andsecond positions. a

10. The timing device of claim 9 wherein said cam operating portion comprises a notch arranged for registry with and to receive said switch blade to permit movement of said switch blade into engagement with said second circuit means,

and lost motion connection means connecting said cam to and for movement with said drive shaft and operative to provide a predetermined amount of angular movement of said cam means with respect to said drive shaft.

References Cited in the file of this patent UNITED STATES PATENTS Swensen Aug. 5, 1941 Harris Mar. 26, 1957 Everard Aug. 12, 1958 Fritz Dec. 20, 1960 Timm et al Apr. 11, 1961 

1. A TIMING DEVICE COMPRISING, IN COMBINATION A TIMING MOTOR, TIMING CAM MEANS CONNECTED TO AND DRIVEN BY SAID TIMING MOTOR, SWITCH MEANS CONNECTED WITH SAID CAM MEANS AND INCLUDING A SWITCH MEMBER MOVABLE SELECTIVELY BETWEEN TWO OPERATIVE CLOSED CIRCUIT POSITIONS IN RESPONSE TO MOVEMENT OF SAID CAM MEANS, SAID SWITCH MEMBER BIASED TOWARD ONE OF ITS OPERATIVE POSITIONS AND MOVABLE AGAINST SAID BIAS TO THE OTHER OF ITS OPERATIVE POSITIONS BY SAID CAM MEANS, 